|Publication number||US7140708 B2|
|Application number||US 10/929,309|
|Publication date||Nov 28, 2006|
|Filing date||Aug 30, 2004|
|Priority date||Aug 30, 2004|
|Also published as||US20060044335|
|Publication number||10929309, 929309, US 7140708 B2, US 7140708B2, US-B2-7140708, US7140708 B2, US7140708B2|
|Inventors||Michael William Lawrence, Brian Keith Owens|
|Original Assignee||Lexmark International, Inc.|
|Export Citation||BiBTeX, EndNote, RefMan|
|Patent Citations (31), Referenced by (4), Classifications (5), Legal Events (7)|
|External Links: USPTO, USPTO Assignment, Espacenet|
1. Field of the Invention
The present invention relates to an imaging apparatus, and, more particularly, to a method of edge-to-edge imaging with an imaging apparatus.
2. Description of the Related Art
An imaging apparatus forms an image on a sheet of print media, such as for example, paper or a transparency, by applying ink or toner onto the print medium. Such an imaging apparatus, in the form of an ink jet printer, forms an image on the sheet of print media by ejecting ink from a plurality of ink jetting nozzles of an ink jet printhead to form a pattern of ink dots on the print medium. Such an ink jet printer typically includes a reciprocating printhead carrier that transports one or more ink jet printheads across the sheet of print media that is supported by a mid-frame along a bi-directional scanning path defining a print zone of the ink jet printer.
For an ink jet printer that is capable of printing in an edge-to-edge mode, a waste ink collection trough, which may include one or more individual reservoirs, is used to capture waste ink along the edges of the sheet of print media in the print zone to prevent inking of the printer mid-frame. The trough is typically designed to be able to capture all of the waste ink that is ejected during edge-to-edge printing over the life of the printer. However, typically there is a physical limitation to the volume that can be used for the waste ink collection trough. If the waste ink collection trough fills completely, then the print quality will degrade to the point that the printer will need to be replaced due to ink smearing onto subsequent sheets of print media. Further, due to media location uncertainty, the edge-to-edge printing algorithm requires a worst-case overspray of ink to insure adequate coverage at the edges, i.e., leading, trailing and lateral edges, of the sheet of print media. For example, if the media size tolerance is +/−1 millimeter (mm) and the media location tolerance is +/−1 mm, then both of these tolerances are added together to determine how far beyond the nominal edge of the sheet of print media that the print swath needs to be extended, or stretched.
One attempt to reduce the amount of waste ink in edge-to-edge printing is to measure the sheet of print media to determine the dimensions of the sheet of print media before generating data for the print job. This measurement is performed by advancing the sheet of print media to a measurement location and then backing the paper up to a print start location prior to beginning the actual printing operation.
What is needed in the art is a method of edge-to-edge imaging with an imaging apparatus, which may dynamically determine the location of the lateral edges of a sheet of print media relative to the mid-frame of the imaging apparatus.
The present invention provides a method of edge-to-edge imaging with an imaging apparatus, which may dynamically determine the location of the lateral edges of a sheet of print media relative to the mid-frame of the imaging apparatus.
The present invention, in one form thereof, relates to an edge-to-edge imaging method implemented with an imaging apparatus that transports a sheet of print media in a sheet feed direction through a print zone. The imaging apparatus includes a mid-frame having a media support surface for supporting the print media in the print zone and having a waste ink collection trough formed in the mid-frame having at least two collection regions spaced to coincide with lateral edges of the sheet of print media. The method includes generating a reflectance profile of the mid-frame by taking optical readings along the mid-frame with no print media present in a direction substantially orthogonal to the sheet feed direction, the reflectance profile distinguishing between the media support surface and the waste ink collection trough; taking optical readings across the mid-frame in the direction substantially orthogonal to the sheet feed direction with the sheet of print media present; comparing the optical readings taken with the sheet of print media present with the reflectance profile of the mid-frame; and applying an algorithm to adjust an amount of ink overspray along the lateral edges of the sheet of print media based on a result of the comparing.
An advantage of the present invention is that the lateral edges of the print media need not be determined prior to starting the print job, e.g., prior to generating data for the print job.
Another advantage is that the lateral edges of the media need not be detected, but rather, the potential media presence is determined by looking for the absence of the waste ink collection trough at discrete points along the mid-frame.
Another advantage is that there is no wait time for measuring before or during a print job.
Another advantage is that the life expectancy of the imaging apparatus is lengthened, since the waste ink collection troughs are not filled as quickly.
Another advantage is the reduction in ink smear by reducing the amount of ink overspray, e.g., ink misting, on the mid-frame.
Another advantage is that the method of the present invention can be performed in conjunction with a print job, so it does not effect throughput and can be done multiple times down the page to periodically readjust for sheet skew.
The above-mentioned and other features and advantages of this invention, and the manner of attaining them, will become more apparent and the invention will be better understood by reference to the following description of embodiments of the invention taken in conjunction with the accompanying drawings, wherein:
Corresponding reference characters indicate corresponding parts throughout the several views. The exemplifications set out herein illustrate embodiments of the invention, and such exemplifications are not to be construed as limiting the scope of the invention in any manner.
Referring now to the drawings, and particularly to
Imaging system 10 includes an imaging apparatus 14, which may be in the form of an ink jet printer, as shown. Thus, for example, imaging apparatus 14 may be a conventional ink jet printer, or may form the print engine for a multi-function apparatus, such as for example, a standalone unit that has faxing and copying capability, in addition to printing.
Host 12, which may be optional, may be communicatively coupled to imaging apparatus 14 via a communications link 16. Communications link 16 may be, for example, a direct electrical connection, a wireless connection, or a network connection.
In embodiments including host 12, host 12 may be, for example, a personal computer including a display device, an input device (e.g., keyboard), a processor, input/output (I/O) interfaces, memory, such as RAM, ROM, NVRAM, and a mass data storage device, such as a hard drive, CD-ROM and/or DVD units. During operation, host 12 includes in its memory a software program including program instructions that function as a printer driver for imaging apparatus 14. The printer driver is in communication with imaging apparatus 14 via communications link 16. The printer driver, for example, includes a halftoning unit and a data formatter that places print data and print commands in a format that can be recognized by imaging apparatus 14. In a network environment, communications between host 12 and imaging apparatus 14 may be facilitated via a standard communication protocol, such as the Network Printer Alliance Protocol (NPAP).
In the embodiment of
Media source 28 is configured to receive a plurality of print medium sheets from which a print medium, i.e., a sheet of print media 30 having a print media surface 30 a, is picked by sheet picking unit 22 and transported to feed roller unit 20, which in turn further transports the sheet of print media 30 during an imaging operation. The sheet of print media 30 may be, for example, plain paper, coated paper, photo paper or transparency media.
Printhead carrier system 18 includes a printhead carrier 32 for mounting and carrying a color printhead 34 and/or a monochrome printhead 36. A color ink reservoir 38 is provided in fluid communication with color printhead 34, and a monochrome ink reservoir 40 is provided in fluid communication with monochrome printhead 36. Those skilled in the art will recognize that color printhead 34 and color ink reservoir 38 may be formed as individual discrete units, or may be combined as an integral unitary printhead cartridge. Likewise, monochrome printhead 36 and monochrome ink reservoir 40 may be formed as individual discrete units, or may be combined as an integral unitary printhead cartridge.
Printhead carrier system 18 further includes a reflectance sensor 42 attached to printhead carrier 32. Reflectance sensor 42 may be, for example, a unitary optical sensor including at least one light source, such as a light emitting diode (LED), and at least one reflectance detector, such as a phototransistor. The reflectance detector is located on the same side of a media as the light source. The operation of such sensors is well known in the art, and thus, will be discussed herein to the extent necessary to relate the operation of reflectance sensor 42 to the operation of the present invention. For example, the LED of reflectance sensor 42 directs light at a predefined angle onto a surface to be read, such as a surface of mid-frame 26 and/or the surface of the sheet of print media 30, and at least a portion of light reflected from the surface is received by the reflectance detector of reflectance sensor 42. The intensity of the reflected light received by the reflectance detector varies with the reflectivity of the surface. The light received by the reflectance detector of reflectance sensor 42 is converted to an electrical signal by the reflectance detector of reflectance sensor 42. The signal generated by the reflectance detector corresponds to the reflectivity of the surface scanned by reflectance sensor 42. Thus, as used herein, the term “reflectivity” refers to the intensity of the light reflected from mid-frame 26 and/or the sheet of print media 30 scanned by reflectance sensor 42, which may be used in accordance with the present invention to dynamically determine the location of the lateral edges of the sheet of print media 30 relative to mid-frame 26 during edge-to-edge printing.
Printhead carrier 32 is guided by a pair of guide members 44, 46, which may be, for example, in the form of guide rods. Each of guide members 44, 46 includes a respective horizontal axis 44 a, 46 a. Printhead carrier 32 includes a pair of guide member bearings 48, 50, each of guide member bearings 48, 50 including a respective aperture for receiving guide member 44. The horizontal axis 44 a of guide member 44 generally defines a bidirectional scan path 52 for printhead carrier 32. Accordingly, scan path 52 is associated with each of printheads 34, 36 and reflectance sensor 42.
Printhead carrier 32 is connected to a carrier transport belt 53 via a carrier drive attachment device 54. Carrier transport belt 53 is driven by a carrier motor 55 via a carrier pulley 56. Carrier motor 55 has a rotating carrier motor shaft 58 that is attached to carrier pulley 56. Carrier motor 55 can be, for example, a direct current (DC) motor or a stepper motor. At the directive of controller 24, printhead carrier 32 is transported in a reciprocating manner along guide members 44, 46, and in turn, along scan path 52.
The reciprocation of printhead carrier 32 transports ink jet printheads 34, 36 and reflectance sensor 42 across the sheet of print media 30, such as paper, along scan path 52 to define a print/sense zone 60 of imaging apparatus 14. The reciprocation of printhead carrier 32 occurs in a main scan direction (bidirectional) that is parallel with bi-directional scan path 52, and is also commonly referred to as the horizontal direction, including a left-to-right carrier scan direction 62 and a right-to-left carrier scan direction 63. Generally, during each scan of printhead carrier 32 while printing or sensing, the sheet of print media 30 is held stationary by feed roller unit 20.
Mid-frame 26 provides support for the sheet of print media 30 when the sheet of print media 30 is in print/sense zone 60, and in part, defines a portion of a print medium path 64 of imaging apparatus 14.
Feed roller unit 20 includes a feed roller 66 and corresponding index pinch rollers (not shown). Feed roller 66 is driven by a drive unit 68. The index pinch rollers apply a biasing force to hold the sheet of print media 30 in contact with respective driven feed roller 66. Drive unit 68 includes a drive source, such as a stepper motor, and an associated drive mechanism, such as a gear train or belt/pulley arrangement. Feed roller unit 20 feeds the sheet of print media 30 in a sheet feed direction 70, designated as an X in a circle to indicate that the sheet feed direction is out of the plane of
Controller 24 includes a microprocessor having an associated random access memory (RAM) and read only memory (ROM). Controller 24 is electrically connected and communicatively coupled to printheads 34, 36 via a communications link 72, such as for example a printhead interface cable. Controller 24 is electrically connected and communicatively coupled to carrier motor 55 via a communications link 74, such as for example an interface cable. Controller 24 is electrically connected and communicatively coupled to drive unit 68 via a communications link 76, such as for example an interface cable. Controller 24 is electrically connected and communicatively coupled to sheet picking unit 22 via a communications link 78, such as for example an interface cable. Controller 24 is electrically connected and communicatively coupled to reflectance sensor 42 via a communications link 80, such as for example an interface cable.
Controller 24 executes program instructions to effect the printing of an image on the sheet of print media 30, such as for example, by selecting the index feed distance of the sheet of print media 30 along print medium path 64 as conveyed by feed roller 66, controlling the acceleration rate and velocity of printhead carrier 32, and controlling the operations of printheads 34, 36, such as for example, by controlling the fire time of individual nozzles of printhead 34 and/or printhead 36. As used herein, the term “fire time” is the time between firings of a nozzle of a printhead in forming adjacent dots on the same scan line of an image. In addition, controller 24 executes instructions, based on reflectance data received from reflectance sensor 42, to dynamically determine the location of the lateral edges of the sheet of print media 30 relative to mid-frame 26 during edge-to-edge printing, and adjust, e.g., minimize, an amount of ink overspray along the lateral edges of the sheet of print media 30.
Each of collection regions 84 b, 84 c, 84 d, 84 e and 84 f of waste ink collection trough 82 may include features to deflect light, e.g., a sloped floor, to further decrease the amount of reflected light received by reflectance sensor 42 from trough 82 in relation to media support surface 86 of mid-frame 26, and thereby further distinguishing trough 82 from the media support surface 86 of mid-frame 26 in terms of reflected light.
At step S100, a reflectance profile of mid-frame 26 is generated by taking optical readings with reflectance sensor 42 with along mid-frame 26 with no print media present at sensor scan path 90 (see
An exemplary reflectance profile of mid-frame 26 is shown in
At step S102, optical readings are taken with reflectance sensor 42 across mid-frame 26 in the direction, e.g., direction 62, substantially orthogonal to sheet feed direction 70 with the sheet of print media 30 present at sensor scan path 90. Reflectance sensor 42 may be used to take optical readings while printhead carrier 32 is moving at normal print speeds, in either of directions 62, 63.
An exemplary reflectance profile of mid-frame 26 with the sheet of print media 30 present at sensor scan path 90 is shown in
At step S104, the optical readings taken with the sheet of print media 30 present at step S102 are compared with the reflectance profile of mid-frame 26 taken at step S100. Thus, step S104 may be performed dynamically during a print job. For example, a change of the reflectivity (ΔR) may be detected, e.g., calculated, by controller 24, and may be processed directly in accordance with step S106, or may be stored in an associated memory. Alternatively, in embodiments including host 12, the change of the reflectivity (ΔR) may be detected by host 12, and processed accordingly.
At step S106, an algorithm is applied to adjust, e.g., minimize, an amount of ink overspray along the lateral edges 88 c, 88 d of the sheet of print media 30 (see
In one exemplary algorithm, the first print swaths of printheads 34, 36 are generated using worst-case estimates for ink overspray, but once the sheet of print media 30 is detected by reflectance sensor 42, a modified algorithm may be used to minimize the overspray. For example, once the optical readings are taken, printing can be enabled to overspray at 0.5 mm or less into the respective collection region of trough 82. For example, if printhead carrier 32 is moving at 40 inches per second, reflectance sensor 42 may be capable of taking 10 readings (samples) per mm. However, the skew specification for the print media may not demand this level of accuracy, so a lower level of sampling may be used. Thus, for example, by taking only 4 optical readings per millimeter, it will be known every quarter millimeter if printhead carrier 32 is over the sheet of print media 30, over a collection region of waste ink collection trough 82, or over media support surface 86 of mid-frame 26. The overspray algorithm may be further modified to account for the mechanical tolerance between the printhead, e.g., printheads 34, 36, and reflectance sensor 42. These likely will be small numbers, but may be adjusted for each program if the minimum amount of overspray is desired.
Once the optical readings are taken (e.g., 4 readings per mm), the skew specification for the print media will determine how much overspray is required to insure media coverage. For example, if skew is a problem for a particular imaging apparatus, e.g., a printer, then multiple optical readings can be taken periodically at intervals along the sheet of print media 30 in sheet feed direction 70 to readjust the amount of overspray periodically as the sheet of print media 30 is advanced in sheet feed direction 70. The amount of overspray can be handled in firmware associated with controller 24 using the print swaths generated by either a printer driver resident on host 12 or the firmware and/or software associated with controller 24, in the case of a stand-alone copy operation.
For a system that has tight tolerances for print media skew, or that makes optical readings periodically at intervals along the sheet of print media 30 in sheet feed direction 70, the amount of overspray may be limited, for example, to 0.5 mm or less. For example, if a particular collection region of waste ink collection trough 82 is known to be 12 mm wide, this translates into 48 readings from reflectance sensor 42 that should read “trough”. Referring to
Thus, one implementation of the present invention would be to limit the valid print locations to a maximum of two “trough” location readings by reflectance sensor 42 at each lateral edge of the sheet of print media 30. When taking optical readings that include the sheet of print media 30, the first two “trough” readings by reflectance sensor 42 before or after a lateral edge “media” optical reading would be considered valid for edge-to-edge print data. Other trough locations would not be considered valid, even if print data is generated for those locations, and no ink would be ejected.
In another implementation, if multiple longitudinally spaced optical readings are taken to account for skew, e.g., optical readings taken periodically at intervals along the sheet of print media 30 in sheet feed direction 70 as the sheet of print media 30 is advanced in sheet feed direction 70, then it is possible to further reduce overspray by limiting to only one “trough” reading that would need to be “printed”, assuming that the mechanical tolerance between reflectance sensor 42 and the printhead will so accommodate this level of accuracy.
The determination of whether a print location is valid may be handled by a filter in the firmware and/or software associated with controller 24. For example, even if print swaths are originally generated to print 103 mm wide, if reflectance sensor 42 detects that the collection regions of waste ink collection trough 82 around the sheet of print media 30 would indicate only 101.5 mm swaths are necessary, then controller 24 can limit the actual ink fired to be 101.5 mm. The fire control block in the firmware can filter out the extra data generated as unnecessary.
It is contemplated that the overspray algorithm may also be used to help eliminate erroneously spraying of ink on mid-frame 26 if a paper jam occurs. For example, reflectance sensor 42 may be used to determine if there is print media present in print/sense zone 60. If reflectance sensor 42 does not detect media entering the print/sense zone 60, or possibly after printing a few swaths, then controller 24 can abort the print job and indicate a paper jam.
While this invention has been described with respect to embodiments of the present invention, the present invention can be further modified within the spirit and scope of this disclosure. This application is therefore intended to cover any variations, uses, or adaptations of the invention using its general principles. Further, this application is intended to cover such departures from the present disclosure as come within known or customary practice in the art to which this invention pertains and which fall within the limits of the appended claims.
|Cited Patent||Filing date||Publication date||Applicant||Title|
|US5847722||Nov 21, 1995||Dec 8, 1998||Hewlett-Packard Company||Inkjet printhead alignment via measurement and entry|
|US5961226||Aug 15, 1997||Oct 5, 1999||Ricoh Company, Ltd.||Printing apparatus|
|US5997129||Oct 20, 1995||Dec 7, 1999||Seiko Epson Corporation||Ink-jet printer for printing across an entire surface of a recording medium|
|US6027203||Dec 11, 1997||Feb 22, 2000||Lexmark International, Inc.||Page wide ink-jet printer and method of making|
|US6046828||Mar 6, 1997||Apr 4, 2000||Xerox Corporation||Method and system for automatically detecting an edge and width of a document utilizing a scanning system|
|US6102509||May 30, 1996||Aug 15, 2000||Hewlett-Packard Company||Adaptive method for handling inkjet printing media|
|US6109745||Jul 17, 1998||Aug 29, 2000||Eastman Kodak Company||Borderless ink jet printing on receivers|
|US6234602||Mar 5, 1999||May 22, 2001||Hewlett-Packard Company||Automated ink-jet printhead alignment system|
|US6239817||Oct 20, 1998||May 29, 2001||Hewlett-Packard Comapny||Apparatus and method for printing borderless print image|
|US6322192||Oct 29, 1998||Nov 27, 2001||Hewlett-Packard Company||Multi-function optical sensing system for inkjet printing|
|US6325505||Oct 29, 1999||Dec 4, 2001||Hewlett-Packard Company||Media type detection system for inkjet printing|
|US6345876||Feb 3, 2000||Feb 12, 2002||Hewlett-Packard Company||Peak-valley finder process for scanned optical relative displacement measurements|
|US6352333||Jan 19, 1999||Mar 5, 2002||Ricoh Company Ltd.||Method and apparatus for preventing nozzle clogging in ink jet printing apparatus|
|US6386663||Jun 27, 2000||May 14, 2002||Hewlett-Packard Company||Adaptive method for handling inkjet printing media|
|US6409305||Feb 9, 2001||Jun 25, 2002||Hewlett-Packard Company||Full bleed printmode to minimize overspray|
|US6457803||May 31, 2000||Oct 1, 2002||Canon Kabushiki Kaisha||Ink jet recording apparatus and ink jet recording method|
|US6527360||Sep 25, 2001||Mar 4, 2003||Seiko Epson Corporation||Printing with sensor-based positioning of printing paper|
|US6575554||Oct 3, 2001||Jun 10, 2003||Canon Kabushiki Kaisha||Ink jet recording apparatus|
|US6626513||Jul 18, 2001||Sep 30, 2003||Lexmark International, Inc.||Ink detection circuit and sensor for an ink jet printer|
|US6682097||Oct 8, 2001||Jan 27, 2004||Breed Automotive Technology, Inc.||Guide sleeve for electric cable emerging from a tube|
|US6840617 *||Apr 2, 2002||Jan 11, 2005||Lexmark International, Inc.||Mid-frame for an imaging apparatus|
|US6930696 *||Sep 21, 2001||Aug 16, 2005||Seiko Epson Corporation||Printing up to edges of printing paper without platen soiling|
|US20030081057||Oct 3, 2002||May 1, 2003||Seiko Epson Corporation||Recording method and recording apparatus|
|US20030095163||Jan 6, 2003||May 22, 2003||Koichi Otsuki||Printing with sensor-based positioning of printing paper|
|US20030113152||Jul 18, 2001||Jun 19, 2003||Adkins Christopher Alan||Automatic horizontal and vertical head-to-head alignment method and sensor for an ink jet printer|
|US20030160837||Jul 18, 2001||Aug 28, 2003||Adkins Christopher Alan||Ink detection circuit and sensor for an ink jet printer|
|US20030184634||Apr 2, 2002||Oct 2, 2003||Crosby Nathan Edward||Mid-frame for an imaging apparatus|
|US20030189611||Apr 8, 2002||Oct 9, 2003||Fan Tai-Lin||Jet printer calibration|
|US20040017443||Jul 8, 2003||Jan 29, 2004||Canon Kabushiki Kaisha||Liquid detection method, liquid detection apparatus and printing apparatus using the liquid detection|
|US20040046829||Aug 25, 2003||Mar 11, 2004||Akihiro Taguchi||Platen and inkjet recording apparatus having that platen|
|US20040056917||Sep 18, 2003||Mar 25, 2004||Wen-Li Su||Ink drop detector configurations|
|Citing Patent||Filing date||Publication date||Applicant||Title|
|US7506947 *||Mar 7, 2005||Mar 24, 2009||Canon Kabushiki Kaisha||Ink jet printing apparatus and method using media shape detection|
|US7794039 *||Sep 2, 2005||Sep 14, 2010||Canon Kabushiki Kaisha||Recording apparatus|
|US20050200680 *||Mar 7, 2005||Sep 15, 2005||Canon Kabushiki Kaisha||Ink jet printing apparatus and ink jet printing method|
|US20060082632 *||Sep 2, 2005||Apr 20, 2006||Hiroyuki Kinoshita||Recording apparatus|
|U.S. Classification||347/14, 347/19|
|Aug 30, 2004||AS||Assignment|
Owner name: JACOBS, ELIZABETH C., KENTUCKY
Free format text: ASSIGNMENT OF ASSIGNORS INTEREST;ASSIGNORS:LAWRENCE, MICHAEL WILLIAM;OWENS, BRIAN KEITH;REEL/FRAME:015767/0835
Effective date: 20040827
|Mar 21, 2005||AS||Assignment|
Owner name: LEXMARK INTERNATIONAL, INC., KENTUCKY
Free format text: CORRECTION OF NAME OF THE ASSIGNEE PREVIOUSLY RECORDED ON REEL 015767 FRAME 0835.;ASSIGNORS:LAWRENCE, MICHAEL WILLIAM;OWENS, BRIAN KEITH;REEL/FRAME:015930/0355
Effective date: 20040827
|May 28, 2010||FPAY||Fee payment|
Year of fee payment: 4
|May 14, 2013||AS||Assignment|
Owner name: FUNAI ELECTRIC CO., LTD, JAPAN
Effective date: 20130401
Free format text: ASSIGNMENT OF ASSIGNORS INTEREST;ASSIGNORS:LEXMARK INTERNATIONAL, INC.;LEXMARK INTERNATIONAL TECHNOLOGY, S.A.;REEL/FRAME:030416/0001
|Jul 11, 2014||REMI||Maintenance fee reminder mailed|
|Jul 22, 2014||FPAY||Fee payment|
Year of fee payment: 8
|Jul 22, 2014||SULP||Surcharge for late payment|
Year of fee payment: 7